1. Field of the Invention
This invention relates to the packaging of bone-in cuts of meat as well as processed meats. In particular, this invention relates to a heat shrinkable bag with a heat shrinkable protective patch which prevents or reduces the likelihood that a bone will completely puncture and rupture a thermoplastic vacuum bag and patch combination.
2. Description of the Related Art
The use of heat shrinkable thermoplastic as flexible packaging materials for vacuum packaging various foodstuffs including meat is well-known. Such plastic materials, however, while in general quite successful for packaging meat understandably have difficulties in successfully packaging sharp or bony products. For example, attempts to package bone-in primal cuts of meat usually result in an unsatisfactorily large number of bag failures due to bone punctures. The use of cushioning materials such as paper, paper laminates, wax impregnated cloth, and various types of plastic inserts have proved to be less than totally satisfactory in solving the problem. The preparation of special cuts of meat or close bone trim with removal of offending bones has also been attempted. However, this is at best only a limited solution to the problem since it does not offer the positive protection necessary for a wide variety of commercial bone-in types of meat. Furthermore, removal of the bone is a relatively expensive and time consuming procedure.
An example of the prior art method of protecting a thermoplastic bag from puncture is shown in U.S. Pat. No. 2,891,870 issued on Jun. 23, 1959 to Meyer S. Selby et al. In the Selby patent the exposed bone in a bone-in cut of meat is covered with a wax impregnated cloth and the thus protected meat is placed in a heat shrinkable plastic bag. Another example of the prior art methods of protecting a thermoplastic bag from puncture is shown in U.S. Pat. No. 4,755,403 issued on Jul. 11, 1988 to Daniel J. Ferguson. The Ferguson patent teaches a method of providing an external multi-layer protective patch for a heat shrinkable thermoplastic bag, said patch being located on what becomes the side of the bag after the product is loaded into the bag. While this patent provides bone caused rupture protection along a small area of the side of the bag such as for example, turkey leg bone punctures, it does nothing to protect a bag containing a end-bone piece of meat such as a ham shank. Another side wall patch teaching may be found in Australian published patent application abstract AU-A-11228/88 published Aug. 4, 1988.